Sofa



FIG. 1 is a perspective view of a sofa showing my new design;

FIG. 2 is a right side elevational view, the left side being a mirror image thereof;

FIG. 3 is a back elevational view;

FIG. 4 is a front elevational view;

FIG. 5 is a bottom plan view; and,

FIG. 6 is a top plan view. 

The ornamental design for a sofa, as shown and described. 